The present invention relates to a post cure inflation rim (hereinafter referred to as "PCI rim") for vehicles.
For carcass material of a tire, nylon, polyester or the like have widely been used. During tire production the temperature of a tire just after vulcanization is very high. So, if the tire is left as it is, heat contraction happens and the tire is significantly deformed.
In view of this problem, just after vulcanization and the temperature of a tire is still high, the tire is assembled with a PCI rim (different from one used in a practical vehicle) for holding and cooling the tire. A constant air pressure is applied to the assembly so that the deformation and the like are prevented.
FIG. 4 is an enlarged cross section of a main part showing a condition where a PCI rim m and a tire t are engaged with each other. As shown in FIG. 4, conventionally, a PCI rim has been designed so that flange radius r.sub.1 is smaller (for example, 5 mm) and flange height l.sub.1 is smaller (for example, 10.5 mm) in view of easy tire detachability, or wide applicability for PCI rims of different diameter.
However, in the case where a tire t just after vulcanization is assembled with the PCI rim m designed as mentioned above, the tire is assembled with a portion from clinched portion a to sidewall b being inclined in a direction of an arrow e. This is shown by a full line in FIG. 4. An imaginary line in FIG. 4 shows an ideal shape of an assembled tire without inclination.
For this reason, as shown in FIG. 5, when the tire t is assembled with a rim n for a practical vehicle, a wide gap f is formed between heel portion d of tire bead c and the rim n. This wide gap f makes the engagement between the tire t and the rim n for the practical vehicle non-uniform in a circumferential direction, and accordingly FV (Force Variation) is great. This results in the tire vibration in its rotation.
An object of the present invention is to solve the above-mentioned problem, namely to provide a PCI rim with which a gap between a heel portion of a tire and a rim for a practical vehicle can be narrowed.